I've been big into crossfit for several years. I've heard all different opinions on Paleo, the zone, and other diets. It all comes down to what works with you and your lifestyle.
I've tried paleo, but to cut out all the processed foods and eat organic is expensive. For the last two weeks I've cut out bread and all those high carb and processed carb foods. I have a cheat day once a week where I'll eat some carbs for dinner or randomly throughout the day. I honestly feel great.
For those saying you can't get enough calories on paleo, you're wrong. By taking out a food, you simply replace it with another. Veggies and meats are absolutely great for you, I would rather eat meat than bread or pasta anyways.
I also don't believe in the dairy portion of it all, most dairy products have additives and high sugar, just be aware of what you're buying. I love chocolate milk and I eat cheese a lot.
and BACON, I love it. I eat roughly a pound or two every couple days.